Fluorine, which is used in the fabrication of semiconductor devices, serves to lower a dielectric constant of a thin oxidized layer and restrict an RC time constant delay. This contributes to improvement in the operating speed of a semiconductor device. However, fluorine has a serious effect on the surroundings structure due to its strong reactivity and diffusion and therefore, requires sufficient capping to prevent the above effect. If fluorine deviates from a use region thereof and is exposed to surrounding metals or transistors or the like, it may shift the transistors or cause defects of the transistors due to strong reactivity thereof. Accordingly, diffusion of fluorine may have a serious negative effect on the performance of a semiconductor device due to causing corrosion of surrounding metals. In particular, when fluorine is exposed to metal, metal corrosion or blistering occurs, causing serious deterioration in the production yield and reliability of a semiconductor device.
FIGS. 1A to 1F illustrate depictions explaining blistering generated upon fabrication of a semiconductor device. FIG. 1A illustrates the appearance of a wafer on and/or over which a semiconductor device having a via pattern is formed. FIG. 1B is an enlarged view of FIG. 1A illustrating blisters 10. FIG. 1C is an enlarged view of FIG. 1B illustrating the blisters 10. FIG. 1D is an enlarged view of FIG. 1C illustrating the blisters 10. FIG. 1E is a sectional view of the semiconductor device shown in FIG. 1D. In addition, it will be appreciated from FIG. 1F which is an enlarged view of FIG. 1E that blisters 12 occur above vias 14. The blisters 12 further seriously occur at a region where via patterns are densely formed. More specifically, if fluorine escapes from an interlayer dielectric layer and attacks the surroundings, the blisters 12 occur.
FIGS. 2A and 2B are plan views of a via pattern produced by a method for manufacturing a semiconductor device. FIG. 2B is an enlarged view of FIG. 2A. Referring to FIG. 2B, in a method for manufacturing a semiconductor device, neighboring vias 14 of a via pattern are spaced apart from each other by a constant distance. Accordingly, when the vias 14 are densely formed, blisters may occur.